CPC G06F 21/629 (2013.01) [G06F 21/53 (2013.01); G06F 21/572 (2013.01); G06F 21/602 (2013.01); G06F 21/72 (2013.01); G06F 2221/0751 (2013.01)] | 22 Claims |
1. A method for handling instances of a trusted execution environment on an execution platform, the trusted execution environment being associated with a secure cryptoprocessor, wherein the secure cryptoprocessor holds a register, and wherein the trusted execution environment is configured to read from and write to the register at a given index i, the method being performed by the trusted execution environment, the method comprising:
checking, upon start of a new instance of the trusted execution environment, status of the register at the given index i, and wherein, when the register at the given index i has its status set to “undefined”, an internal status value is set to a first value, and else, when a value is read from the register at the given index i, the internal status value is set to a second value based on the read value;
writing the internal status value to the register at the given index i;
running the new instance, and whilst doing so:
reading a current value from the register at the given index i; and
enabling the new instance to keep running only when the current value equals the internal status value.
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